Metal forming press



10, 1967 F. J. FUCHS, JR, ETAL 3,

METAL FORMING PRES 5 Filed Nov. 29, 1965 3 Sheets-Sheet l ATTORNEY 1967 F. J. FUCHS, JR, ETAL 3,296,852

METAL FORMING PRES S Filed Nov. 29, 1963 5 Sheets-Sheet 2 y 7 HQ if 4 4 r L "w R Jan. 10, 1967 F. J. FUCHS, JR., ETAL 3,296,352

METAL FORMING PRESS Filed Nov. 29, 1963 3 Sheets5heet 5 i LIL W United States Patent Ofilice 3,296,852 Patented Jan. 19, 1967 York Filed Nov. 29, 1963, Ser. No. 326,824 7 Claims. (Cl. 72-398) This invention relates to a metal forming press and more particularly to a wave-guide forming press capable of producing extremely high forming pressures without setting up deleterious stress concentrations in a waveguide being formed.

In the manufacture of waveguides it is necessary to form the guides with thin walls and with transitions such as from a circular cross section to a square cross section. Between the extremities of the waveguide, gradual and precise transitions must be formed in order to secure the desired waveguide propagation characteristics. Inasmuch as relatively large areas of stock material must be formed, the fabrication of many types of waveguides do not lend themselves to cold forming because of the difiiculty in producing the required high forming pressures. Another difficulty encountered in the use of cold forming techniques is the formation of areas of uneven stress concentration which often result in a crinklin g of the waveguide surface. A crinkled surface condition cannot be tolerated if effective microwave transmission is to be attained throughout the waveguide. At present it is the usual practice that when difficult waveguide fabrication IPIOblBIl'lS are encountered, that expensive, timeconsuming electroforming operations are used.

It is an object of this invention to provide a new and improved metal forming press.

Another object of the invention resides in a forming press capable of producing extremely high pressures without subjecting the stock being formed to uneven stress patterns.

A further object of the invention is the provision of a forming press having a stationary die and a movable die together with facilities for maintaining a mandrel equidistant between the dies during a forming operation.

An additional object of the invention is the provision of a high pressure forming pres-s utilizing a pair of inclined planes to move a movable die at a first predetermined rate and a mandrel at a second predetermined rate with respect to a stationary die which cooperates with the movable die and the mandrel to fabricate a Waveguide with extremely smooth walls and with a transition from a first cross sectional configuration to a second cross sectional configuration.

With these and other objects in view the present invention contemplates a high pressure metal forming press for cold forming round cross sectional hollow stock into a waveguide having a circular to square cross sectional transition. The press includes a stationary upper die holder and a movable lower die holder, together with the facilities for maintaining a mandrel equally spaced between the die holders. The movementof the lower die holder and the mandrel is attained by the use of a wedge having two inclined surfaces. The steeper inclined surface directly moves the lower die holder, whereas the other inclined surface directly moves the mandrel.

In addition, the invention contemplates individual die elements being slidalbly mounted in both die holders to cooperate with each other upon movement of the lower die holder to act on a piece of hollow metal stock mounted on the mandrel. Further, a mounting is provided for the mandrel so that it may be axially moved into engagement with a breech block to confine the cold flow of the metal stock during the shaping operation performed by the cooperating dies.

Other objects and advantages of the present invention will be apparent from the following detailed description when considered in conjunction with the accompanying drawings wherein:

-FIG. 1 is a perspective view of a waveguide that may be fabricated by the forming press shown in the other figures;

FIG. 2 is a side elevational view partially cut away showing a cold forming press encompassing the principles of the present invention;

FIG. 3 is a top plan view of the forming press shown in FIG. 2;

FIG. 4- is a front end View of the forming press shown in FIGS. 2 and 3 particularly illustrating the forward surfaces of a wedge device for actuating the press;

FIG. 5 is a rear end view of a forming press taken along line 55 of FIG. 1 depicting a cross sectional showing of the wedge device and a piston rod for supporting a mandrel;

FIG. 6 is a cross sectional view taken along line 6-6 of FIG. 2 illustrating a set of four slidably mounted dies in an open position;

FIG. 7 is a cross sectional view similar to FIG. 6 but with the slidably mounted dies illustrated in a closed position;

FIG. 8 is a sectional view taken along line 8-S of FIG. 3 showing the transitional configuration of the dies together with a partial showing of a breech block that cooperates with the dies to confine metal flow; and

FIG. 9 is a cross sectional view taken along line 99 of FIG. 8 showing the breech block.

Referring first to FIG. 1, there is shown a waveguide 10 of the type that may be fabricated by the forming press constituting the present invention. It will be noted that one end 11 is formed with a square configuration whereas the other end 12 has a circular cross sectional configuration. Between the ends 11 and 12, there 1s a gradual transition which must be formed without imparting any uneven stress concentrations. If there are uneven stresses and a crinkled surface condition results, the

electrical propagation characteristics of the waveguide are impaired.

The forming press is mounted on a solid base or founda tion 13 to which is attached a base plate 14 having vertical, headed tie bolts 16 extending therethrou gh to provide a support for a top plate 17. The top plate 17 is restrained from movement by nuts 18 engaging threaded ends of the tie bolts 16.

Slidably mounted on the base plate 14 is a wedging device 19 comprising three wedges 21, 22 and 23. Wedges 21 and 23 have identical inclined surfaces, whereas the wedge 22 has a steeper incline; that is, twice that of the incline of the wedges 21 and 23. The wedge 22 is connected to a piston rod 24 that is operated by hydraulic fluid being admitted to a cylinder 26. A follower block 27, having an inclined surface 28, rests on the wedge 22. Secured to the follower block 27 is a first die holder or means 29 that is in alignment with a second die holder or means 31 secured to the top plate 17. Mounted between the die holders 29 and 31 is a mandrel 32 attached to a piston rod 33 adapted to be operated by hydraulic fluid being admitted to a cylinder 34. The cylinder 34 is secured to a bracket 36 attached to a rear slide or end plate 37. The slide plate 37 is provided with a tapered or conical opening 35 to snugly receive the tapered end of the mandrel. When the mandrel is moved toward the right by the piston 12, any stock on the mandrel will be stripped or forced ofi.

Referring to FIG. 5, the rear slide plate 37 is shown cut out to provide two inclined surfaces 38 and 39 that respectively cooperate with the wedges 21 and 23. The plate 37 is also cut into to provide an opening 40 which permits the free passage of the wedge 22. Extending through the rear slide plate 37 is a plurality of horizontal tie rods 41 that are fastened to a front slide or end plate 42 by nuts 43. Referring to FIG. 4, it will be noted that front slide plate 42 is cut out to provide a pair of surfaces 44 and 45 that cooperate with the wedges 23 and 22. Another cutout section 46 provides clearance for the wedge 22.

It will be noted that end plates 37 and 42, together with base plate 14 and top plate 17, are arranged to provide a housing for the die holders 29 and 31 and the mandrel 32.

Considering now the die holder means 29 and 31, and with particular reference to FIG. 6, these die holder means are provided with V-shaped slots 46 and 47. Secured to opposite walls 48 and 49 of the slots 46 and 47 are two fixed dies 51 and 52. The ends of the dies 51 and 52 are spaced from walls 53 and 54 of the slots 46 and 47 to provide passageways to receive two additional dies 56 and 57. Springs 58 and 59 are provided to urge the ends of the dies 56 and 57 into engagement withthe dies 52 and 51, respectively. When the die holders 29 and 31 are moved toward each other, the dies 51 and 52 will act against the dies 57 and 56 to compress the springs 59 and 58 in the manner depicted in FIG. 7.

Referring now to FIG. 4, the front end plate 42 is shown provided with a circular opening 61 having enlargements 62 and 63 for the reception of interrupted flange sections 64 and 65 of a breech block 66 shown in FIGS. 1 and 8. The breech block 66 is provided with a circumferential groove 67 to accommodate the end plate 42 when the breech block is inserted in the opening 61. The breech block 66 is provided with handles 68 and 69 which will permit an operator to rotate the breech block to move the interrupted flange sections 64 and 65 from within the enlargements 62 and 63 to a position behind the end plate 42.

The breech block 66 is also provided with a facer plate 71 (see FIG. 8) which abuts against the ends of the dies 51, 52, 56 and 57. When the mandrel 32 is fully inserted within the forming chamber formed between the dies 51, 52, 56 and 57, the end abuts against the facer plate 71 to completely confine the forming chamber.

In use of the forming press, the breech block 66 is removed by turning the handles 68 and 69 to position the interrupted flange sections 64 and 65 into alignment with the enlargements 62 and 63 of the opening 61, and then withdrawing the block from the end plate 42. Now with the wedges 21, 22 and 23 withdrawn by the piston rod 24 and hydraulic cylinder 26, the die holders 22 and 31 are spaced apart so that the dies are open as depicted in FIG. 6. The operator may now place a generally cylindrically shaped piece of hollow stock on the mandrel 32. The breech block 66 is replaced in the end plate 42 and turned so that the interrupted flange sections 64 and 65 are positioned in back of the end plate 42. Hydraulic fluid is admitted to the cylinder 26 to drive the piston rod 24 and the wedges 21, 22 and 23 toward the left. The wedge 28 acts on the follower block 27 to move the die holder 29 along the end plates 37 and 42 toward the die holder 31. The dies 56 and 57 will move against the action of the springs 58 and 59 and cooperate with the dies 51 and 52 to form and shape the waveguide 10. The longitudinal configuration of the dies is best illustrated in FIG. 8. As wedges 21 and 23 advance toward the left, the end plates 37 and 34 are moved upwardly and as a result the mandrel 32 is also moved. Inasmuch as the incline of the wedegs 21 and 23 is one half that of wedge 22, the mandrel 32 will move at one half the rate that the die holder 29 is moved. It may be thus appreciated that the mandrel 32 will be equally spaced between the die holders 29 and 31 during all movements of the die holder 29.

Upon completion of the forming operation, the hydraulic cylinder 26 is operated to withdraw the piston rod and wedges to open the dies. Next, the hydraulic cylinder 34 is operated to receive fluid to move the piston rod 31 toward the right. The mandrel 32 also moves toward the right and the circular end 12 of the fabricated waveguide 10 abuts against the inner face of the end plate 37 about the opening 35 to strip the waveguide 10 from the mandrel 32. The breech block 66 may now be removed and the fabricated waveguide 10 removed from the mandrel 32.

It is to be understood that the above-described arrangements of apparatus and construction of elemental parts are simply illustrative of an application of theinvention, and many other modifications may be madewithout departing from the invention.

What is claimed is:

1. In a forming press,

a pair of spaced end plates having a first and second inclined lower surface,

means for securing said end plates together,

a top plate mounted between said end plates,

means for holding said top plate stationary,

a first die holder mounted on said top plate,

a second die holder having an inclined surface mounted between said end plates for movement along said end plates toward and away from said stationary stop plate,

a mandrel mounted on one of said end plates and projecting between said die holders, and

a wedging device cooperating with said first and second inclined surfaces for moving the second die holder at twice the rate of the movement of said mandrel.

2. In a metal forming press,

a housing including top and bottom plates,

a pair of end plates slidably mounted for movement on said top and bottom plates,

a stationary die holder means mounted on the underside of said top plate,

a movable die holder means mounted between said end plates for movement toward said stationary die holder means,

said movable die holder means having an inclined lower surface at first predetermined pitch,

said end plates having inclined lower surfaces at a second predetermined pitch which is one-half the pitch of said first predetermined pitch,

a first wedge having an incline corresponding to said first predetermined pitch for engaging said inclined surface of said movable die holder,

a second wedge having an incline corresponding to said second predetermined pitch for engaging the inclined surfaces of said end plates,

a mandrel mounted on one of said end plates and projecting between said die holder means, and

means for simultaneously moving said first and sec ond wedges to advance said lower die holder at twice the rate of advancement of said end plates and mandrel.

3. In a forming press,

a housing having an opening formed therein,

a fixed die means mounted within said housing,

7 a movable die means mounted within said housing and spaced from said fixed die to define a chamber about said opening,

a movable mandrel projecting into said chamber toward said opening,

a removable breech block mounted in said opening to cooperate with the end of said mandrel to define a confined forming space between said die means and the end of the mandrel, and

means for advancing said movable die means toward said fixed die means While advancing said mandrel toward said fixed die means at one-half the rate of movement of said die means.

4. In a forming press,

a pair of spaced end plates having inclined surfaces formed along the lower ends thereof,

a fixed top plate mounted between said end plates,

a first die holder means mounted on the underside of said top plate,

a second die holder means slidably mounted between said end plate and having an inclined underside,

a mandrel mounted on the first of said end plates and projecting between said die holder means toward the second of said end plates for supporting metal stock,

said second end plate having an opening formed therein in alignment with said mandrel,

a removable breech block positioned within said opening and having a facer plate abutting the end of said mandrel for confining metal flow of said stock to the space between said mandrel and said die holder means,

a first wedge means engaging and cooperating with said inclined surfaces on said end plates for moving said end plates and said mandrel at a first predetermined rate, and

a second Wedge means engaging and cooperating with the inclined surface on said second die holders for moving said second die holder at a predetermined rate which is twice that of said first predetermined rate.

5. In a forming press,

a first die holder means having a fixed die and movable die,

a second die holder means spaced from said first die holder having a fixed die and a movable die,

means for urging said movable dies into engagement with the fixed dies mounted in the opposite die holders to define a chamber between said dies,

a mandrel for supporting a workpiece in said chamber,

means for moving said die holders relative to each other to move said movable dies to reduce the size of said forming chamber, and

means for moving said mandrel to center said mandrel between said die holders during said relative movement of said die holders.

6. In a forming press,

a stationary die holder having a first V-shaped longitudinal groove,

a first die secured to one wall of said groove and having an end spaced from the other wall of the groove,

a movably mounted die holder spaced from said stationary holder having a second V-shaped longitudinal groove in alignment with said first groove,

a second die secured to a wall of the second groove in opposition to the first die and having an end spaced from the other wall of said second groove,

a pair of slidably mounted dies respectively positioned within the spaces between the ends of the fixed dies and said other walls,

spring means engaging the said slidably mounted dies for urging the ends of said dies into engagement with the fixed dies to define a confined forming chamber between all of said dies,

means for advancing said movably mounted die holder toward said fixed die holder to move said slidably mounted dies against said spring means to reduce the size of said forming chamber, and

means for supporting a workpiece within said chamher.

7. In a forming press for fabricating a thin wall waveguide,

a first stationary die holder means including a pair of dies mounted at right angles, one of which is slidably mounted with respect to the other,

a second movable mounted die holder means including a pair of dies mounted at right angles, one of which is slidably mounted with respect to the other,

resilient means on both of said die holder means for urging said slidably mounted dies into engagement with the stationary dies mounted on the opposite die holder means,

a pair of spaced end plates abutting the ends of the die holders and slidably mounted thereon,

one of said end plates having an opening formed therea mandrel mounted on said one end plate and projecting through said opening into the space between said dies for supporting metal stock,

means for moving said second die holder means to- Ward the first die holder means at a first rate to slide said slidably mounted dies against the resilient means whereby said dies are moved toward the mandrel to form said metal stock,

means for moving said end plates at one-half the rate of said second die holder means to maintain the mandrel equidistant from said dies, and

means for moving the mandrel through said opening to strip the formed metal stock from said mandrel.

References Cited by the Examiner UNITED STATES PATENTS 1,964,584 6/ 1934 Klocke 72370 2,558,845 7/1951 Gruetjen 72--398 2,767,763 10/ 1956 Anderson 72404 2,961,028 11/1960 Bath 72297 2,986,194 5/1961 De Marco 72-297 3,220,239 11/1965 Olsen et al. 72--404 FOREIGN PATENTS 346,455 1/ 1922 Germany.

CHARLES W. LANHAM, Primary Examiner.

RICHARD J. HERBST, Examiner. 

1. IN A FORMING PRESS, A PAIR OF SPACED END PLATES HAVING A FIRST AND SECOND INCLINED LOWER SURFACE, MEANS FOR SECURING SAID END PLATES TOGETHER, A TOP PLATE MOUNTED BETWEEN SAID END PLATES, MEANS FOR HOLDING SAID TOP PLATE STATIONARY, A FIRST DIE HOLDER MOUNTED ON SAID TOP PLATE, A SECOND DIE HOLDER HAVING AN INCLINED SURFACE MOUNTED BETWEEN SAID END PLATES FOR MOVEMENT ALONG SAID END PLATES TOWARD AND AWAY FROM SAID STATIONARY STOP PLATE, A MANDREL MOUNTED ON ONE OF SAID END PLATES AND PROJECTING BETWEEN SAID DIE HOLDERS, AND A WEDGING DEVICE COOPERATING WITH SAID FIRST AND SECOND INCLINED SURFACES FOR MOVING THE SECOND DIE HOLDER AT TWICE THE RATE OF THE MOVEMENT OF SAID MANDREL. 